1.2-Propanediol Online sale now
|Product Name||1,2-Propanediol (Propylene glycol)|
|Categories||Building Blocks Organics|
|Harmonised Tariff Code||29053200|
|Chloride (Cl)||0.007% max|
|Residue on Ignition||70ppm max|
|Appearance||Clear colourless viscous liquid|
|Ethylene glycol, Diethylene glycol||0.008% max|
|Heavy metals (as Pb)||<10ppm|
|Refraction index||1.4310-1.4320 nD20|
|Density 20°C||1.0350-1.0370 g/cm3|
1,2-Propanediol is an important building block as a component used in the production of unsaturated polyester resin, antifreeze, biofuel, nonionic detergent, etc. The commercial production of 1,2-propanediol via microbial biosynthesis is limited by low efficiency, and the chemical production of 1,2-propanediol requires petrochemical-derived pathways involving wasteful energy consumption and high pollution emissions. With the development of various strategies based on metabolic engineering, a number of obstacles are expected to be overcome. This review provides a comprehensive overview of the progress in microbial production of 1,2-propanediol, in particular the different microorganisms used for 1,2-propanediol biosynthesis and the microbial production pathways. In addition, outstanding challenges associated with microbial biosynthesis and feasible metabolic engineering strategies are discussed, as well as perspectives for future microbial production of 1,2-propanediol.
The traditional petrochemical industry needs further reforms due to public concerns about environmental pollution and the scarcity of petroleum resources [1, 2]. However, due to the wider spectrum of biomass sources, safer production processes and lower environmental impacts, today the bio-based chemical industry is becoming more and more powerful in the field of chemical production . Currently, the increasing production of chemicals from biomass via biotechnological routes is attracting the attention of researchers, and these chemicals include biofuels (ethanol, butanol) [4, 5], drugs (vitamins) , organic acids (lactic and succinic acids). acid) [7, 8], diols (1,2-propanediol, 1,3-propanediol) [9, 10] and other platform bulk and specialty chemicals.
1,2-Propanediol (1,2-PDO), as a C3 diol, is an important chemical platform with high demand in industry . So far, 1,2-PDO has been widely used in the construction, chemical and pharmaceutical industries as a monomer for use in the production of polyester resins, antifreezes, liquid detergents, biofuels, cosmetics, food, etc. [11,12, 13,14,15] Annually, more than 1.36 million tons of racemic 1,2-PDO alone are produced due to global demand and reached about USD 0.373 billion globally in 2020 and is expected to reach more than USD 0.398 billion by 2026. CAGR (Compound Annual Growth Rate) of 1.6%. Currently, the commercial route to 1,2-PDO involves the hydration of fossil fuel-based propylene using chemical methods . The use of fossil resources as starting material in these methods not only pollutes the environment, but also leads to a racemic mixture . In addition, there are two stereoisomers in 1,2-PDO: R-1,2-PDO and S-1,2-PDO. Compared to the racemic products, the pure stereoisomers of this chemical show greater potential as chiral synthons in the organic synthesis of chiral pharmaceutical products. However, the use of these pure stereoisomers is often limited due to their high cost and low availability, except at the laboratory scale . For these reasons, special attention has emerged with regard to the production of 1,2-PDO, especially in the form of the pure stereoisomer from biomass through biological processes.
Although the production of 1,2-PDO by various bacteria and yeasts has been achieved for many years, the biological process is still very challenging due to the lack of naturally efficient synthetic routes. For example, microbial production of 1,2-PDO has not been applied to industrial-scale production due to low yield. However, in recent years, along with the rapid development of metabolic strategies, including the modification of natural pathways and the design of artificial pathways, the production of pure stereoisomer 1,2-PDO from inexpensive substrates via biological routes is now possible for industrial applications. . Recent efforts on strain exploration, process optimization, pathway identification, and various metabolic engineering strategies to improve microbial 1,2-PDO production are summarized here. Disadvantages, challenges and future trends towards economical production of 1,2-PDO by biotechnological routes are also discussed.